Theosis

THEOSIS — Partaking of the Divine Nature

Theosis (or deification), becoming “partakers of the divine nature” (II Pet. 1:4), is an ancient theological term that you will often hear as an Orthodox Christian, and it is very important that you understand what this term means and does not mean. Although the doctrine of theosis came to be neglected in the post-Schism Western Church, it was clearly taught as late as the 13th century in the dissident Roman Patriarchate. Thomas Aquinas taught theosis — "full participation in divinity which is mankind's true beatitude and the destiny of human life" (Summa Theologiae 3.1.2).

The concept of theosis is also found in the traditional (Pre-Vatican II) Roman Liturgy. In the prayer, Deus, Qui Humanœ Substantiœ, the priest prays as he mixes water with the wine in the chalice:

“O GOD, who didst lay the foundations of man’s being in wonder and honour, and in greater wonder and honour didst renew the same: grant that by the mystery of this water and wine, that he who was partaker of our humanity may make us joint-heirs of his very Godhead, even Jesus Christ thy Son our Lord: Who liveth and reigneth with thee in the unity of the Holy Ghost, God, world without end. Amen.

In its efforts to restore the faith of the primitive Church, theosis is found as a recurring theme within Anglicanism: in Lancelot Andrewes (17th c.), the hymnody of John and Charles Wesley (18th c.), Edward B. Pusey (19th c.), and A. M. Allchin and E. Charles Miller (20th c.). The prayer, Deus, Qui Humanœ Substantiœ, is also found in both the Anglican and American Missals.

Christians are to become by grace what Jesus Christ is by nature — sons and daughters of God. Christ partook of our human nature that we might partake of His divine nature. This is not to be confused with the heretical apothéōsis — "Deification in God’s Essence,” which is imparticipable.

OrthodoxWiki has a good short article on Theosis, along with links to additional articles on the subject. The OrthodoxWiki article on Theosis can be found here: